Purpose: The purpose of the study was to investigate the relationships between sports passion, sports motivation, and subjective well-being; it also examined the moderating effects of sports motivation on sports passion and subjective well-being. In total, 411 college athletes were enrolled and asked to complete the Sports Passion Scale, Sports Motivation Scale, and Subjective Well-Being Scale surveys. The Pearson correlation coefficient and hierarchical regression were used for analysis in this study. Results: 1. Among the participants, sports motivation was significantly correlated with subjective well-being and with sports passion; however, sports motivation was not significantly correlated with subjective well-being. 2. Sports motivation moderated the relationship between sports passion and subjective well-being. Conclusion: On the basis of the results, future studies should investigate the moderating effects of perceived sports motivational climate and social support on the relationship between sports passion and subjective well-being; they should also explore methods for improving the passion and well-being of college athletes.